I was running optimax extreme for a while and I thought the car ran better. Then I read on another forum that the V8 supercars had to stop using this fuel because it was eating too many fuel supply components. I've gone back to 98RON now and it's interesting that Shell have now rebadged optimax extreme as optimax racing.
1981 930 headers, K27, 1 bar spring
1988 951S work in progress